Jasmonic acid boosts the salt tolerance of kidney beans (Phaseolus vulgaris L.) by upregulating its osmolytes and antioxidant mechanism.

As a lipid-derived compound, jasmonic acid (JA) regulates growth and defense against environmental stresses. An exogenous foliar JA application was investigated in our study (HA; 0.5 mM) on kidney bean plants (Phaseolus vulgaris L.) grown under different salinity stress concentrations (0, 75, and 150 mM NaCl). According to the results, salt concentrations were related to an increase in malondialdehyde (MDA) levels, whereas they declined the chlorophyll content index. In contrast, JA application decreased the level of MDA but increased the chlorophyll content index. Moreover, increasing salinity levels increased proline, phenolic compounds, flavonoids, free amino acid concentrations, and shikimic acid concentrations, as well as the activities of polyphenol oxidase (PPO), ascorbate peroxidase (APX), catalase (CAT), and peroxidase (POD). In addition, JA applications further increased their concentrations with increasing salinity stress levels. JA application increases salt-induced osmolytes and non-enzymatic antioxidants while increasing enzymatic antioxidant activity, suggesting kidney beans have a strong antioxidant mechanism, which can adapt to salinity stress. Our results showed that exogenous JA foliar applications could enhance the salt tolerance ability of kidney bean plants by upregulating their antioxidant mechanism and osmolytes.

Impact of Cadmium Stress on Growth and Physio-Biochemical Attributes of Eruca sativa Mill.

Plants may experience adverse effects from Cadmium (Cd). As a result of its toxicity and mobility within the soil-plant continuum, it is attracting the attention of soil scientists and plant nutritionists. In this study, we subjected young Eruca sativa Mill. seedlings to different levels of Cd applications (0, 1.5, 6 and 30 µmol/L) via pot experiment to explore its morpho-physio-biochemical adaptations. Our results revealed a significant Cd accumulation in leaves at high Cd stress. It was also demonstrated that Cd stress inhibited photosynthetic rate and pigment levels, ascorbate peroxidase (APX), guaiacol peroxidase (GPX), catalase (CAT), and superoxide dismutase (SOD) enzyme activities, and increased malondialdehyde (MDA) levels. Conversely, the concentration of total ascorbate (TAS) increased at all levels of Cd application, whereas that of ascorbic acid (ASA), and dehydroascorbate (DHA) increased at 1.5 (non-significant), 6, 30 and 6 µmol/L (significant), though their concentrations decreased non-significantly at 30 µmol/L application. In conclusion, Cd-subjected E. sativa seedlings diverted much energy from growth towards the synthesis of anti-oxidant metabolites and osmolytes. However, they did not seem to have protected the E. sativa seedlings from Cd-induced oxidative stress, causing a decrease in osmotic adjustment, and an increase in oxidative damage, which resulted in a reduction in photosynthesis and growth. Accordingly, we recommend that the cultivation of E. sativa should be avoided on soil with Cd contamination.

Heterologous expression and characterization of glycoside hydrolase with its potential applications in hyperthermic environment.

With the progressive focus on renewable energy via biofuels production from lignocellulosic biomass, cellulases are the key enzymes that play a fundamental role in this regard. This study aims to unravel the characteristics of Thermotoga maritima MSB8 (Tma) (a hyperthermophile from hot springs) thermostable glycoside hydrolase enzyme. Here, a glycoside hydrolase gene of Thermotoga maritima (Tma) was heterologously expressed and characterized. The gene was placed in the pQE-30 expression vector under the T5 promotor, and the construct pQE-30-Gh was then successfully integrated into Escherichia coli BL21 (DH5α) genome by transformation. Sequence of the glycoside hydrolase contained an open reading frame of 2.124 kbp, encoded a polypeptide of 721 amino acid residues. The molecular weight of the recombinant protein estimated was 79 kDa. The glycoside hydrolase was purified by Ni+2-NTA affinity chromatography and its enzymatic activity was investigated. The recombinant enzyme is highly stable within an extreme pH range (2.0-7.0) and highly thermostable at 80 °C for 72 h indicating its viability in hyperthermic environment and acidic nature. Moreover, the Ca2+ and Mn2+ introduction stimulated the residual activity of recombinant enzyme. Conclusively, the thermostable glycoside hydrolase possesses potential to be exploited for industrial applications at hyperthermic environment.

Comprehensive Detoxification Mechanism Assessment of Red Imported Fire Ant (Solenopsis invicta) against Indoxacarb.

The red imported fire ant (Solenopsis invicta) is one of the deadliest invasive ant species that threatens the world by disrupting biodiversity, important functions within a natural ecosystem, and community structure. They are responsible for huge economic losses in the infested countries every year. Synthetic insecticides, especially indoxacarb, have been broadly used to control S. invicta for many years. However, the biochemical response of S. invicta to indoxacarb remains largely undiscovered. Here, we used the sublethal doses of indoxacarb on the S. invicta collected from the eight different cities of Southern China. The alteration in the transcriptome profile of S. invicta following sublethal dosages of indoxacarb was characterized using high-throughput RNA-seq technology. We created 2 libraries, with 50.93 million and 47.44 million clean reads for indoxacarb treatment and control, respectively. A total of 2018 unigenes were regulated after insecticide treatment. Results indicated that a total of 158 differentially expressed genes (DEGs) were identified in the indoxacarb-treated group, of which 100 were significantly upregulated and 58 were downregulated, mostly belonging to the detoxification enzymes, such as AChE, CarE, and GSTs. Furthermore, results showed that most of these DEGs were found in several KEGG pathways, including steroid biosynthesis, other drug metabolizing enzymes, glycerolipid metabolism, chemical carcinogenesis, drug-metabolizing cytochrome P450, glutathione metabolism, glycerophospholipid metabolism, glycolysis/gluconeogenesis, and metabolism of xenobiotics. Together, these findings indicated that indoxacarb causes significant alteration in the transcriptome profile and signaling pathways of S. invicta, providing a foundation for further molecular inquiry.

Bemisia tabaci-mediated facilitation in diversity of begomoviruses: Evidence from recent molecular studies.

Begomoviruses are considered as one of the most notorious plant viruses worldwide, which cause substantial economic losses to various field crops. Management of begomoviruses has become a challenge due to the continuous evolution and the emergence of new strains. Bemisia tabaci is globally known to be the key vector of begomoviruses, having relatively high reproductivity, fast dispersal ability, high survival rate due to its polyphagous nature and high resistance to various groups of insecticides. Continuous transmission of begomoviruses by the vector has led to the development and spread of epidemics of various diseases worldwide. In this review, we have critically analyzed the various dynamics which facilitate the diversity of begomoviruses through their vector. The interaction of begomovirus-whitefly leads to continuous research activities regarding management of both virus and its vector, thus opening exciting new horizons to formulate potential control strategies to ensure a disease-free cropping environment.

Genetic diversity of begomoviruses in Pakistan captured through a vector based survey.

Begomoviruses (Geminiviridea), transmitted by whiteflies, constitute one of the most dangerous groups of plant viruses posing a severe threat to economically important crops in tropical and sub-tropical areas. In this study, whiteflies were collected from various locations all over Pakistan. The begomoviruses carried by these whiteflies were detected by PCR with the degenerative primers pair AV94/Dep3. Analysis of the 177 sequences obtained in our study, revealed 14 distinct begomovirus species, including five which were not previously reported in this country. Putative novel strains of Corchorus yellow vein virus (CoYVV) and Chilli leaf curl virus (ChiLCV) showing less than 90% identity with the previously available taxa were also identified. The greatest number of begomoviruses per single site was detected in Sindh province, where up to five different begomovirus species were identified from the same cropping field. Moreover, Cotton leaf curl Multan virus - Rajasthan (CLCuMuV-Ra) was found prevalent in all the cotton growing areas. The data reported here may be useful in the development of control measures against begomoviruses.